低溫銣原子與雷德堡鉀原子的交互作用

雷德堡原子因為具有極強的偶極矩，使得雷德堡原子之間具有非常強力的偶極–偶極作用力。這樣的特性使得雷德堡原子在量子資訊領域引起了不少關注。因為極強的偶極–偶極作用力，使得雷德堡原子之間產生一個有趣的現象稱作雷德堡阻絕，這個現象使得中性原子成為量子位元的候選人之一。在這篇論文中，我們藉由觀察在冷原子團中因為雷德堡原子造成磁光陷阱中的原子損失來研究在冷原子團底下的雷德堡躍遷。我們測量三組不同的雷德堡躍遷所早成的原子損失。我們觀察到對於那些主量子數較高雷德堡原子，其會造成較大的原子損失。同時比較兩個能量相近但原子軌域不同的雷德堡態原子，D軌域較S軌域有更大的原子損失。我們也藉由鉀跟銣原子展示了在磁光陷阱中異核原子間的交互作用。鉀跟銣原子會對彼此產生影響，彼此之間的數量呈現競爭關係。藉由把鉀原子激發到雷德堡態，我們得以研究鉀在不同的雷德堡態下造成銣的原子損失。雷德堡態鉀原子對磁光陷阱中銣原子的影響會隨著雷德堡態的主量子數越大而越強。

關鍵字

鉀原子；雷德堡原子

並列摘要

Rydberg atom has drawn attraction of researchers in the field of quantum information owing to its large dipole moment which allows a strong dipole-dipole interaction. This interaction leads to an interesting phenomenon, known as Rydberg Blockade, which makes trapped neutral atoms a good candidate for quantum qubits. In this thesis, we study various Rydberg transitions of 39K in the cold ensemble by observing the trap loss of the magneto-optical trap(MOT) induced by Rydberg atoms. Trap loss measurement is performed using three sets of Rydberg transitions. For a high principal quantum number n state, large trap loss is observed. Meanwhile by comparing with the nearby energy level state of D states, the trap loss is larger than that of S states. We have demonstrated the heteronuclear interaction using Potassium and Rubidium in the MOT. The 39K and 87Rb MOT are influenced by each other, the number of the atoms of two species are in a competitive relationship. With the excited 39K to the Rydberg state, we have studied the trap loss of 87Rb MOT with different Rydberg state of 39K. The Rydberg state of higher principal quantum number n has a stronger influence of the 87Rb MOT.